Publications

@article{pmid39341849,

title = {Constraining the trend in the ocean CO sink during 2000-2022},

author = {Nicolas Mayot and Erik T Buitenhuis and Rebecca M Wright and Judith Hauck and Dorothee C E Bakker and Corinne Le Quéré},

doi = {10.1038/s41467-024-52641-7},

issn = {2041-1723},

year  = {2024},

date = {2024-09-01},

journal = {Nat Commun},

volume = {15},

number = {1},

pages = {8429},

abstract = {The ocean will ultimately store most of the CO emitted to the atmosphere by human activities. Despite its importance, estimates of the 2000-2022 trend in the ocean CO sink differ by a factor of two between observation-based products and process-based models. Here we address this discrepancy using a hybrid approach that preserves the consistency of known processes but constrains the outcome using observations. We show that the hybrid approach reproduces the stagnation of the ocean CO sink in the 1990s and its reinvigoration in the 2000s suggested by observation-based products and matches their amplitude. It suggests that process-based models underestimate the amplitude of the decadal variability in the ocean CO sink, but that observation-based products on average overestimate the decadal trend in the 2010s. The hybrid approach constrains the 2000-2022 trend in the ocean CO sink to 0.42 ± 0.06 Pg C yr decade, and by inference the total land CO sink to 0.28 ± 0.13 Pg C yr decade.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37150207,

title = {Climate-driven variability of the Southern Ocean CO sink},

author = {N Mayot and C Le Quéré and C Rödenbeck and R Bernardello and L Bopp and L M Djeutchouang and M Gehlen and L Gregor and N Gruber and J Hauck and Y Iida and T Ilyina and R F Keeling and P Landschützer and A C Manning and L Patara and L Resplandy and J Schwinger and R Séférian and A J Watson and R M Wright and J Zeng},

doi = {10.1098/rsta.2022.0055},

issn = {1471-2962},

year  = {2023},

date = {2023-06-01},

journal = {Philos Trans A Math Phys Eng Sci},

volume = {381},

number = {2249},

pages = {20220055},

abstract = {The Southern Ocean is a major sink of atmospheric CO, but the nature and magnitude of its variability remains uncertain and debated. Estimates based on observations suggest substantial variability that is not reproduced by process-based ocean models, with increasingly divergent estimates over the past decade. We examine potential constraints on the nature and magnitude of climate-driven variability of the Southern Ocean CO sink from observation-based air-sea O fluxes. On interannual time scales, the variability in the air-sea fluxes of CO and O estimated from observations is consistent across the two species and positively correlated with the variability simulated by ocean models. Our analysis suggests that variations in ocean ventilation related to the Southern Annular Mode are responsible for this interannual variability. On decadal time scales, the existence of significant variability in the air-sea CO flux estimated from observations also tends to be supported by observation-based estimates of O flux variability. However, the large decadal variability in air-sea CO flux is absent from ocean models. Our analysis suggests that issues in representing the balance between the thermal and non-thermal components of the CO sink and/or insufficient variability in mode water formation might contribute to the lack of decadal variability in the current generation of ocean models. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{essd-15-5301-2023,

title = {Global Carbon Budget 2023},

author = {P. Friedlingstein and M. O'Sullivan and M. W. Jones and R. M. Andrew and D. C. E. Bakker and J. Hauck and P. Landschützer and C. Le Quéré and I. T. Luijkx and G. P. Peters and W. Peters and J. Pongratz and C. Schwingshackl and S. Sitch and J. G. Canadell and P. Ciais and R. B. Jackson and S. R. Alin and P. Anthoni and L. Barbero and N. R. Bates and M. Becker and N. Bellouin and B. Decharme and L. Bopp and I. B. M. Brasika and P. Cadule and M. A. Chamberlain and N. Chandra and T. -T. -T. Chau and F. Chevallier and L. P. Chini and M. Cronin and X. Dou and K. Enyo and W. Evans and S. Falk and R. A. Feely and L. Feng and D. J. Ford and T. Gasser and J. Ghattas and T. Gkritzalis and G. Grassi and L. Gregor and N. Gruber and Ö. Gürses and I. Harris and M. Hefner and J. Heinke and R. A. Houghton and G. C. Hurtt and Y. Iida and T. Ilyina and A. R. Jacobson and A. Jain and T. Jarníková and A. Jersild and F. Jiang and Z. Jin and F. Joos and E. Kato and R. F. Keeling and D. Kennedy and K. Klein Goldewijk and J. Knauer and J. I. Korsbakken and A. Körtzinger and X. Lan and N. Lef`evre and H. Li and J. Liu and Z. Liu and L. Ma and G. Marland and N. Mayot and P. C. McGuire and G. A. McKinley and G. Meyer and E. J. Morgan and D. R. Munro and S. -I. Nakaoka and Y. Niwa and K. M. O'Brien and A. Olsen and A. M. Omar and T. Ono and M. Paulsen and D. Pierrot and K. Pocock and B. Poulter and C. M. Powis and G. Rehder and L. Resplandy and E. Robertson and C. Rödenbeck and T. M. Rosan and J. Schwinger and R. Séférian and T. L. Smallman and S. M. Smith and R. Sospedra-Alfonso and Q. Sun and A. J. Sutton and C. Sweeney and S. Takao and P. P. Tans and H. Tian and B. Tilbrook and H. Tsujino and F. Tubiello and G. R. Werf and E. Ooijen and R. Wanninkhof and M. Watanabe and C. Wimart-Rousseau and D. Yang and X. Yang and W. Yuan and X. Yue and S. Zaehle and J. Zeng and B. Zheng},

url = {https://essd.copernicus.org/articles/15/5301/2023/},

doi = {10.5194/essd-15-5301-2023},

year  = {2023},

date = {2023-01-01},

journal = {Earth System Science Data},

volume = {15},

number = {12},

pages = {5301--5369},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1029/2022GB007596b,

title = {Fingerprint of Climate Change on Southern Ocean Carbon Storage},

author = {R. M. Wright and C. Le Quéré and N. Mayot and A. Olsen and D. C. E. Bakker},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2022GB007596},

doi = {https://doi.org/10.1029/2022GB007596},

year  = {2023},

date = {2023-01-01},

journal = {Global Biogeochemical Cycles},

volume = {37},

number = {4},

pages = {e2022GB007596},

abstract = {Abstract The Southern Ocean plays a critical role in the uptake, transport, and storage of carbon by the global oceans. It is the ocean's largest sink of CO2, yet it is also among the regions with the lowest storage of anthropogenic carbon. This behavior results from a unique combination of high winds driving the upwelling of deep waters and the subduction and northward transport of surface carbon. Here we isolate the direct effect of increasing anthropogenic CO2 in the atmosphere from the indirect effect of climate variability and climate change on the reorganization of carbon in the Southern Ocean interior using a combination of modeling and observations. We show that the effect of climate variability and climate change on the storage of carbon in the Southern Ocean is nearly as large as the effect of anthropogenic CO2 during the period 1998–2018 compared with the climatology around the year 1995. We identify a distinct climate fingerprint in dissolved inorganic carbon (DIC), with elevated DIC concentration in the ocean at 300–600 m that reinforces the anthropogenic CO2 signal, and reduced DIC concentration in the ocean around 2,000 m that offsets the anthropogenic CO2 signal. The fingerprint is strongest at lower latitudes (30°–55°S). This fingerprint could serve to monitor the highly uncertain evolution of carbon within this critical ocean basin, and better identify its drivers.},

note = {e2022GB007596 2022GB007596},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35271335,

title = {Climate change and biospheric output},

author = {Le Quéré, C. and Mayot, N.},

doi = {10.1126/science.abo1262},

issn = {1095-9203},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Science},

volume = {375},

number = {6585},

pages = {1091--1092},

abstract = {The response of terrestrial and marine ecosystems to rising carbon dioxide (CO2) concentrations has serious implications for projections of climate change in the coming decades. Ecosystems store vast amounts of carbon, which, if destabilized, could amplify climate change (1). They also provide multiple services to society, from food and shelter to recreation and well-being. Changes in ecosystems and their productivity at the global scale could have fundamental implications for society’s future. On page 1145 of this issue, Yang et al. (2) reconstruct changes in global biosphere productivity during the past eight glaciations over about 800,000 years and provide insights into the sensitivity of global ecosystems to CO2 concentrations and climate change.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{essd-14-4811-2022,

title = {Global Carbon Budget 2022},

author = {P. Friedlingstein and M. O'Sullivan and M. W. Jones and R. M. Andrew and L. Gregor and J. Hauck and C. Le Quéré and I. T. Luijkx and A. Olsen and G. P. Peters and W. Peters and J. Pongratz and C. Schwingshackl and S. Sitch and J. G. Canadell and P. Ciais and R. B. Jackson and S. R. Alin and R. Alkama and A. Arneth and V. K. Arora and N. R. Bates and M. Becker and N. Bellouin and H. C. Bittig and L. Bopp and F. Chevallier and L. P. Chini and M. Cronin and W. Evans and S. Falk and R. A. Feely and T. Gasser and M. Gehlen and T. Gkritzalis and L. Gloege and G. Grassi and N. Gruber and Ö. Gürses and I. Harris and M. Hefner and R. A. Houghton and G. C. Hurtt and Y. Iida and T. Ilyina and A. K. Jain and A. Jersild and K. Kadono and E. Kato and D. Kennedy and K. Klein Goldewijk and J. Knauer and J. I. Korsbakken and P. Landschützer and N. Lef`evre and K. Lindsay and J. Liu and Z. Liu and G. Marland and N. Mayot and M. J. McGrath and N. Metzl and N. M. Monacci and D. R. Munro and S. -I. Nakaoka and Y. Niwa and K. O'Brien and T. Ono and P. I. Palmer and N. Pan and D. Pierrot and K. Pocock and B. Poulter and L. Resplandy and E. Robertson and C. Rödenbeck and C. Rodriguez and T. M. Rosan and J. Schwinger and R. Séférian and J. D. Shutler and I. Skjelvan and T. Steinhoff and Q. Sun and A. J. Sutton and C. Sweeney and S. Takao and T. Tanhua and P. P. Tans and X. Tian and H. Tian and B. Tilbrook and H. Tsujino and F. Tubiello and G. R. Werf and A. P. Walker and R. Wanninkhof and C. Whitehead and A. Willstrand Wranne and R. Wright and W. Yuan and C. Yue and X. Yue and S. Zaehle and J. Zeng and B. Zheng},

url = {https://essd.copernicus.org/articles/14/4811/2022/},

doi = {10.5194/essd-14-4811-2022},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Earth System Science Data},

volume = {14},

number = {11},

pages = {4811--4900},

abstract = {Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ.



For the year 2021, EFOS increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr−1 (9.9 ± 0.5 GtC yr−1 when the cement carbonation sink is included), and ELUC was 1.1 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr−1 (40.0 ± 2.9 GtCO2). Also, for 2021, GATM was 5.2 ± 0.2 GtC yr−1 (2.5 ± 0.1 ppm yr−1), SOCEAN was 2.9  ± 0.4 GtC yr−1, and SLAND was 3.5 ± 0.9 GtC yr−1, with a BIM of −0.6 GtC yr−1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at https://doi.org/10.18160/GCP-2022 (Friedlingstein et al., 2022b).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1029/2021JC017486,

title = {Regionalization of the Red Sea Based on Phytoplankton Phenology: A Satellite Analysis},

author = {M. Kheireddine and N. Mayot and M. Ouhssain and B. H. Jones},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021JC017486},

doi = {https://doi.org/10.1029/2021JC017486},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {126},

number = {10},

pages = {e2021JC017486},

abstract = {Abstract The current average state of Red Sea phytoplankton phenology needs to be resolved in order to study future variations that could be induced by climate change. Moreover, a regionalization of the Red Sea could help to identify areas of interest and guide in situ sampling strategies. Here, a clustering method used 21 years of satellite surface chlorophyll-a concentration observations to characterize similar regions of the Red Sea. Four relevant phytoplankton spatiotemporal patterns (i.e., bio-regions) were found and linked to biophysical interactions occurring in their respective areas. Two of them, located in the northern part the Red Sea, were characterized by a distinct winter-time phytoplankton bloom induced by mixing events or associated with a convergence zone. The other two, located in the southern regions, were characterized by phytoplankton blooms in summer and winter which might be under the influence of water advected into the Red Sea from the Gulf of Aden in response to the seasonal monsoon winds. Some observed inter-annual variabilities in these bio-regions suggested that physical mechanisms could be highly variable in response to variations in air-sea heat fluxes and ENSO phases in the northern and southern half of the Red Sea, respectively. This study reveals the importance of sustaining in situ measurements in the Red Sea to build a full understanding about the physical processes that contribute to phytoplankton production in this basin.},

note = {e2021JC017486 2021JC017486},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.3389/fmars.2020.608032c,

title = {Under-Ice Phytoplankton Blooms: Shedding Light on the “Invisible” Part of Arctic Primary Production},

author = {M. Ardyna and C.J. Mundy and N. Mayot and L. C. Matthes and L. Oziel and C. Horvat and E. Leu and P. Assmy and V. Hill and P. A. Matrai and M. Galeand I. A. Melnikov and K. R. Arrigo},

url = {https://www.frontiersin.org/articles/10.3389/fmars.2020.608032},

doi = {https://doi.org/10.3389/fmars.2020.608032},

issn = {2296-7745},

year  = {2020},

date = {2020-11-19},

urldate = {2020-11-19},

journal = {Frontiers in Marine Science},

volume = {7},

abstract = {The growth of phytoplankton at high latitudes was generally thought to begin in open waters of the marginal ice zone once the highly reflective sea ice retreats in spring, solar elevation increases, and surface waters become stratified by the addition of sea-ice melt water. In fact, virtually all recent large-scale estimates of primary production in the Arctic Ocean (AO) assume that phytoplankton production in the water column under sea ice is negligible. However, over the past two decades, an emerging literature showing significant under-ice phytoplankton production on a pan-Arctic scale has challenged our paradigms of Arctic phytoplankton ecology and phenology. This evidence, which builds on previous, but scarce reports, requires the Arctic scientific community to change its perception of traditional AO phenology and urgently revise it. In particular, it is essential to better comprehend, on small and large scales, the changing and variable icescapes, the under-ice light field and biogeochemical cycles during the transition from sea-ice covered to ice-free Arctic waters. Here, we provide a baseline of our current knowledge of under-ice blooms (UIBs), by defining their ecology and their environmental setting, but also their regional peculiarities (in terms of occurrence, magnitude, and assemblages), which is shaped by a complex AO. To this end, a multidisciplinary approach, i.e., combining expeditions and modern autonomous technologies, satellite, and modeling analyses, has been used to provide an overview of this pan-Arctic phenological feature, which will become increasingly important in future marine Arctic biogeochemical cycles. year = 2020},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1029/2019JC015799,

title = {Springtime Export of Arctic Sea Ice Influences Phytoplankton Production in the Greenland Sea},

author = {N. Mayot and P. A. Matrai and A. Arjona and S. Bélanger and C. Marchese and T. Jaegler and M. Ardyna and M. Steele},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015799},

doi = {https://doi.org/10.1029/2019JC015799},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {125},

number = {3},

pages = {e2019JC015799},

abstract = {Abstract Climate model projections suggest a substantial decrease of sea ice export into the outflow areas of the Arctic Ocean over the 21st century. Fram Strait, located in the Greenland Sea sector, is the principal gateway for ice export from the Arctic Ocean. The consequences of lower sea ice flux through Fram Strait on ocean dynamics and primary production in the Greenland Sea remain unknown. By using the most recent 16 years (2003–2018) of satellite imagery available and hydrographic in situ observations, the role of exported Arctic sea ice on water column stratification and phytoplankton production in the Greenland Sea is evaluated. Years with high Arctic sea ice flux through Fram Strait resulted in high sea ice concentration in the Greenland Sea, stronger water column stratification, and an earlier spring phytoplankton bloom associated with high primary production levels. Similarly, years with low Fram Strait ice flux were associated with a weak water column stratification and a delayed phytoplankton spring bloom. This work emphasizes that sea ice and phytoplankton production in subarctic “outflow seas” can be strongly influenced by changes occurring in the Arctic Ocean.},

note = {e2019JC015799 2019JC015799},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{essd-10-627-2018,

title = {Hydrography and biogeochemistry dedicated to the Mediterranean BGC-Argo 

network during a cruise with RV textitTethys 2 in May 2015},

author = {V. Taillandier and T. Wagener and F. DÓrtenzio and N. Mayot and H. Legoff and J. Ras and L. Coppola and O. Pasqueron de Fommervault and C. Schmechtig and E. Diamond and H. Bittig and D. Lefevre and E. Leymarie and A. Poteau and L. Prieur},

url = {https://essd.copernicus.org/articles/10/627/2018/},

doi = {10.5194/essd-10-627-2018},

year  = {2018},

date = {2018-01-01},

journal = {Earth System Science Data},

volume = {10},

number = {1},

pages = {627--641},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/2016JC012671,

title = {Multiscale Observations of Deep Convection in the Northwestern Mediterranean Sea During Winter 2012–2013 Using Multiple Platforms},

author = {P. Testor and A. Bosse and L. Houpert and F. Margirier and L. Mortier and H. Legoff and D. Dausse and M. Labaste and J. Karstensen and D. Hayes and A. Olita and A. Ribotti and K. Schroeder and J. Chiggiato and R. Onken and E. Heslop and B. Mourre and F. D'Ortenzio and N. Mayot and H. Lavigne and O. Fommervault and L. Coppola and L. Prieur and V. Taillandier and X. Durrieu de Madron and F. Bourrin and G. Many and P. Damien and C. Estournel and P. Marsaleix and I. Taupier-Letage and P. Raimbault and R. Waldman and M.-N. Bouin and H. Giordani and G. Caniaux and S. Somot and V. Ducrocq and P. Conan},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012671},

doi = {https://doi.org/10.1002/2016JC012671},

year  = {2018},

date = {2018-01-01},

urldate = {2018-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {123},

number = {3},

pages = {1745-1776},

abstract = {Abstract During winter 2012–2013, open-ocean deep convection which is a major driver for the thermohaline circulation and ventilation of the ocean, occurred in the Gulf of Lions (Northwestern Mediterranean Sea) and has been thoroughly documented thanks in particular to the deployment of several gliders, Argo profiling floats, several dedicated ship cruises, and a mooring array during a period of about a year. Thanks to these intense observational efforts, we show that deep convection reached the bottom in winter early in February 2013 in a area of maximum 28 ± 3 . We present new quantitative results with estimates of heat and salt content at the subbasin scale at different time scales (on the seasonal scale to a 10 days basis) through optimal interpolation techniques, and robust estimates of the deep water formation rate of 2.0 . We provide an overview of the spatiotemporal coverage that has been reached throughout the seasons this year and we highlight some results based on data analysis and numerical modeling that are presented in this special issue. They concern key circulation features for the deep convection and the subsequent bloom such as Submesoscale Coherent Vortices (SCVs), the plumes, and symmetric instability at the edge of the deep convection area.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{AYATA20187,

title = {Regionalisation of the Mediterranean basin, a MERMEX synthesis},

author = {S.-D. Ayata and J.-O. Irisson and A. Aubert and L. Berline and J.-C. Dutay and N. Mayot and A.-E. Nieblas and F. D'Ortenzio and J. Palmiéri and G. Reygondeau and V. Rossi and C. Guieu},

url = {https://www.sciencedirect.com/science/article/pii/S0079661117300393},

doi = {https://doi.org/10.1016/j.pocean.2017.09.016},

issn = {0079-6611},

year  = {2018},

date = {2018-01-01},

urldate = {2018-01-01},

journal = {Progress in Oceanography},

volume = {163},

pages = {7-20},

abstract = {Regionalisation aims at delimiting provinces within which physical conditions, chemical properties, and biological communities are reasonably homogeneous. This article proposes a synthesis of the many recent regionalisations of the open-sea regions of the Mediterranean Sea. The nine studies considered here defined regions based on different, and sometimes complementary, criteria: dynamics of surface chlorophyll concentration, ocean currents, three-dimensional hydrological and biogeochemical properties, or the distribution of organisms. Although they identified different numbers and patterns of homogeneous regions, their compilation in the epipelagic zone identifies nine consensus frontiers, eleven consensus regions with relatively homogeneous conditions, and four heterogeneous regions with highly dynamical conditions. The consensus frontiers and regions are in agreement with well-known hydrodynamical features of the Mediterranean Sea, which constrain the distribution of hydrological and ecological variables. The heterogeneous regions are rather defined by intense mesoscale activity. The synthesis proposed here could constitute a reference step for management actions and spatial planning, such as the application of the European Marine Strategy Framework Directive, and for future biogeochemical and ecological studies in the Mediterranean Sea.},

note = {Special issue of MERMEX project: Recent advances in the oceanography of the Mediterranean Sea},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1029/2018JC014271,

title = {Assessing Phytoplankton Activities in the Seasonal Ice Zone of the Greenland Sea Over an Annual Cycle},

author = {N. Mayot and P. Matrai and I. H. Ellingsen and M. Steele and K. Johnson and S. C. Riser and D. Swift},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC014271},

doi = {https://doi.org/10.1029/2018JC014271},

year  = {2018},

date = {2018-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {123},

number = {11},

pages = {8004-8025},

abstract = {Abstract In seasonal ice zones (SIZs), such as the one of the Greenland Sea, the sea ice growth in winter and subsequent melting in summer influence the phytoplankton activity. However, studies assessing phytoplankton activities over complete annual cycles and at a fine temporal resolution are lacking in this environment. Biogeochemical-Argo floats, which are able to sample under the ice, were used to collect physical and biogeochemical data along vertical profiles and at 5-day resolution during two complete annual cycles in the Greenland Sea SIZ. Three phytoplankton activity phases were distinct within an annual cycle: one under ice, a second at the ice edge, and a third one around an open-water subsurface chlorophyll maximum. As expected, the light and nitrate availabilities controlled the phytoplankton activity and the establishment of these phases. On average, most of the annual net community production occurred equally under ice and at the ice edge. The open-water subsurface chlorophyll maximum phase contribution, on the other hand, was much smaller. Phytoplankton biomass accumulation and production thus occur over a longer period than might be assumed if under ice blooms were neglected. This also means that satellite-based estimates of phytoplankton biomass and production in this SIZ are likely underestimated. Simulations with the Arctic-based physical-biologically coupled SINMOD model suggest that most of the annual net community production in this SIZ results from local processes rather than due to advection of nitrate from the East Greenland and Jan Mayen Currents.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/2016JC012664,

title = {Open-ocean convection process: A driver of the winter nutrient supply and the spring phytoplankton distribution in the Northwestern Mediterranean Sea},

author = {T. Severin and F. Kessouri and M. Rembauville and E. D. Sánchez-Pérez and L. Oriol and J. Caparros and M. Pujo-Pay and J.-F. Ghiglione and F. D'Ortenzio and V. Taillandier and N. Mayot and X. Durrieu De Madron and C. Ulses and C. Estournel and P. Conan},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012664},

doi = {https://doi.org/10.1002/2016JC012664},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {122},

number = {6},

pages = {4587-4601},

abstract = {Abstract This study was a part of the DeWEX project (Deep Water formation Experiment), designed to better understand the impact of dense water formation on the marine biogeochemical cycles. Here, nutrient and phytoplankton vertical and horizontal distributions were investigated during a deep open-ocean convection event and during the following spring bloom in the Northwestern Mediterranean Sea (NWM). In February 2013, the deep convection event established a surface nutrient gradient from the center of the deep convection patch to the surrounding mixed and stratified areas. In the center of the convection area, a slight but significant difference of nitrate, phosphate and silicate concentrations was observed possibly due to the different volume of deep waters included in the mixing or to the sediment resuspension occurring where the mixing reached the bottom. One of this process, or a combination of both, enriched the water column in silicate and phosphate, and altered significantly the stoichiometry in the center of the deep convection area. This alteration favored the local development of microphytoplankton in spring, while nanophytoplankton dominated neighboring locations where the convection reached the deep layer but not the bottom. This study shows that the convection process influences both winter nutrients distribution and spring phytoplankton distribution and community structure. Modifications of the convection's spatial scale and intensity (i.e., convective mixing depth) are likely to have strong consequences on phytoplankton community structure and distribution in the NWM, and thus on the marine food web.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/2016JC012634,

title = {A submesoscale coherent vortex in the Ligurian Sea: From dynamical barriers to biological implications},

author = {A. Bosse and P. Testor and N. Mayot and L. Prieur and F. D'Ortenzio and L. Mortier and H. Le Goff and C. Gourcuff and L. Coppola and H. Lavigne and P. Raimbault},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012634},

doi = {https://doi.org/10.1002/2016JC012634},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {122},

number = {8},

pages = {6196-6217},

abstract = {Abstract In June 2013, a glider equipped with oxygen and fluorescence sensors has been used to extensively sample an anticyclonic Submesoscale Coherent Vortex (SCV) in the Ligurian Sea (NW Mediterranean Sea). Those measurements are complemented by full-depth CTD casts (T, S, and oxygen) and water samples documenting nutrients and phytoplankton pigments within the SCV and outside. The SCV has a very homogeneous core of oxygenated waters between 300 and 1200 m formed 4.5 months earlier during the winter deep convection event. It has a strong dynamical signature with peak velocities at 700 m depth of 13.9 cm s−1 in cyclogeostrophic balance. The eddy has a small radius of 6.2 km corresponding to high Rossby number of −0.45. The vorticity at the eddy center reaches . Cross-stream isopycnic diffusion of tracers between the eddy core and the surroundings is found to be very limited due to dynamical barriers set by the SCV associated with a diffusivity coefficient of about 0.2 m2 s−1. The deep core is nutrients-depleted with concentrations of nitrate, phosphate, and silicate, 13–18% lower than the rich surrounding waters. However, the nutriclines are shifted of about 20–50 m toward the surface thus increasing the nutrients availability for phytoplankton. Chlorophyll-a concentrations at the deep chlorophyll maximum are subsequently about twice bigger as compared to outside. Pigments further reveal the predominance of nanophytoplankton inside the eddy and an enhancement of the primary productivity. This study demonstrates the important impact of postconvective SCVs on nutrients distribution and phytoplankton community, as well as on the subsequent primary production and carbon sequestration.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/2016JC012668,

title = {Influence of the Phytoplankton Community Structure on the Spring and Annual Primary Production in the Northwestern Mediterranean Sea},

author = {N. Mayot and F. D'Ortenzio and J. Uitz and B. Gentili and J. Ras and V. Vellucci and M. Golbol and D. Antoine and H. Claustre},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012668},

doi = {https://doi.org/10.1002/2016JC012668},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {122},

number = {12},

pages = {9918-9936},

abstract = {Abstract Satellite ocean color observations revealed that unusually deep convection events in 2005, 2006, 2010, and 2013 led to an increased phytoplankton biomass during the spring bloom over a large area of the northwestern Mediterranean Sea (NWM). Here we investigate the effects of these events on the seasonal phytoplankton community structure, we quantify their influence on primary production, and we discuss the potential biogeochemical impact. For this purpose, we compiled in situ phytoplankton pigment data from five ship surveys performed in the NWM and from monthly cruises at a fixed station in the Ligurian Sea. We derived primary production rates from a light photosynthesis model applied to these in situ data. Our results confirm that the maximum phytoplankton biomass during the spring bloom is larger in years associated with intense deep convection events (+51%). During these enhanced spring blooms, the contribution of diatoms to total phytoplankton biomass increased (+33%), as well as the primary production rate (+115%). The occurrence of a highly productive bloom is also related to an increase in the phytoplankton bloom area (+155%) and in the relative contribution of diatoms to primary production (+63%). Therefore, assuming that deep convection in the NWM could be significantly weakened by future climate changes, substantial decreases in the spring production of organic carbon and of its export to deep waters can be expected.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/2016JC012052,

title = {Physical and Biogeochemical Controls of the Phytoplankton Blooms in North Western Mediterranean Sea: A Multiplatform Approach Over a Complete Annual Cycle (2012–2013 DEWEX Experiment)},

author = {N. Mayot and F. D'Ortenzio and V. Taillandier and L. Prieur and O. Pasqueron Fommervault and H. Claustre and A. Bosse and P. Testor and P. Conan},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012052},

doi = {https://doi.org/10.1002/2016JC012052},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Journal of Geophysical Research: Oceans},

volume = {122},

number = {12},

pages = {9999-10019},

abstract = {Abstract The North Western Mediterranean Sea exhibits recurrent and significant autumnal and spring phytoplankton blooms. The existence of these two blooms coincides with typical temperate dynamics. To determine the potential control of physical and biogeochemical factors on these phytoplankton blooms, data from a multiplatform approach (combining ships, Argo and BGC-Argo floats, and bio-optical gliders) were analyzed in association with satellite observations in 2012–2013. The satellite framework allowed a simultaneous analysis over the whole annual cycle of in situ observations of mixed layer depth, photosynthetical available radiation, particle backscattering, nutrients (nitrate and silicate), and chlorophyll-a concentrations. During the year 2012–2013, satellite ocean color observations, confirmed by in situ data, have revealed the existence of two areas (or bioregions) with comparable autumnal blooms but contrasting spring blooms. In both bioregions, the ratio of the euphotic zone (defined as the isolume 0.415 mol photons m−2 d−1, Z0.415) and the MLD identified the initiation of the autumnal bloom, as well as the maximal annual increase in [Chl-a] in spring. In fact, the autumnal phytoplankton bloom might be initiated by mixing of the summer shallowing deep chlorophyll maximum, while the spring restratification (when Z0.415/MLD ratio became >1) might induce surface phytoplankton production that largely overcomes the losses. Finally, winter deep convection events that took place in one of the bioregions induced higher net accumulation rate of phytoplankton in spring associated with a diatom-dominated phytoplankton community principally. We suggest that very deep winter MLD lead to an increase in surface silicates availability, which favored the development of diatoms.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid27096373,

title = {In situ imaging reveals the biomass of giant protists in the global ocean},

author = {T. Biard and L. Stemmann and M. Picheral and N. Mayot and P. Vandromme and H. Hauss and G. Gorsky and L. Guidi and R. Kiko and F. Not},

doi = {10.1038/nature17652},

issn = {1476-4687},

year  = {2016},

date = {2016-04-01},

urldate = {2016-04-01},

journal = {Nature},

volume = {532},

number = {7600},

pages = {504--507},

abstract = {Planktonic organisms play crucial roles in oceanic food webs and global biogeochemical cycles. Most of our knowledge about the ecological impact of large zooplankton stems from research on abundant and robust crustaceans, and in particular copepods. A number of the other organisms that comprise planktonic communities are fragile, and therefore hard to sample and quantify, meaning that their abundances and effects on oceanic ecosystems are poorly understood. Here, using data from a worldwide in situ imaging survey of plankton larger than 600 μm, we show that a substantial part of the biomass of this size fraction consists of giant protists belonging to the Rhizaria, a super-group of mostly fragile unicellular marine organisms that includes the taxa Phaeodaria and Radiolaria (for example, orders Collodaria and Acantharia). Globally, we estimate that rhizarians in the top 200 m of world oceans represent a standing stock of 0.089 Pg carbon, equivalent to 5.2% of the total oceanic biota carbon reservoir. In the vast oligotrophic intertropical open oceans, rhizarian biomass is estimated to be equivalent to that of all other mesozooplankton (plankton in the size range 0.2-20 mm). The photosymbiotic association of many rhizarians with microalgae may be an important factor in explaining their distribution. The previously overlooked importance of these giant protists across the widest ecosystem on the planet changes our understanding of marine planktonic ecosystems. },

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{bg-13-1901-2016,

title = {Interannual variability of the Mediterranean trophic regimes from ocean color satellites},

author = {N. Mayot and F. D'Ortenzio and M.R. d'Alcala and H. Lavigne and H. Claustre},

url = {https://bg.copernicus.org/articles/13/1901/2016/},

doi = {10.5194/bg-13-1901-2016},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {Biogeosciences},

volume = {13},

number = {6},

pages = {1901--1917},

keywords = {},

pubstate = {published},

tppubtype = {article}

}